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New technology for night-time drivers
Driving at night is demanding and dangerous and some choose to avoid it altogether, writes Andrew Stucken
Away from urban areas and some arterial roads, lighting is often poor or non-existent. Full-beam blinds other drivers and dipped lights offer poor illumination. It is no surprise that night time casualty rates soar, with up to ten times as many fatal accidents between midnight and 6am.
But car firms are now marketing models with technology that dramatically improves motorists' night vision.
BMW is offering a night-vision system on its 7 series plus some 5 and 6 Series models. Mercedes are joining in with their S-Class and Coupé. Lexus has developed an object recognition system and other manufacturers are looking at night vision technology.
The systems work by detected infra-red rays – invisible to human eyes. Infra-red is a form of electromagnetic energy emitted when any object is heated.
Two competing technologies are battling it out – passive vision and active vision – and they handle the data in very different ways.
Mercedes cars are fitted with two extra halogen headlights with full beam intensity, but are filtered to emit only infra-red rays. A fairly standard digital camera then comes into play, specially adjusted to see only infra-red wavelengths. It captures the light reflected from objects ahead.
Images are then displayed on an LCD panel behind the steering wheel – rather like a black and white TV screen. The effect is to be driving around at night using full beam headlights but without blinding other drivers, with the view illuminated up to 500 feet ahead.
BMW has meanwhile opted for the passive vision system, also known as far infra-red. Passive night vision is more complex and more expensive version, relying on more sophisticated cameras to intensify the infrared images. The company believes the best method is to reduce the images to their relevant detail.
The essential difference from Mercedes' model is that it shows up only warm objects rather than a whole picture - ie people, animals and other vehicles.
For both version of the technology, opinion is generally that it works and is of definite use on unlit roads.
The Royal Society for the Prevention of Accidents (RoSPA) has cautiously welcomed the development - but is concerned it will prompt faster night driving.
Scientists meanwhile claim the systems will one day be fitted as standard on family cars.
* Written by technology journalist Andrew Stucken. Andrew's opinions are his own and for general information only.
